Mechanical pencil having means for sharpening the lead



June 20, 1950 E. H. KUPER 2,512,208

MECHANICAL PENCIL HAVING MEANS FOR SHARPENING THE LEAD Filed April 24, 1947 2 Sheets-Sheet 1 fLMEA hf Kz/PE/P 34W n Fla] 5m 4 4 TTOANE Y June 20, 1950 E. H. KUPER MECHANICAL PENCIL HAVING MEANS FOR SHARPENING THE LEAD Filed April 24, 1947 2 Sheets-Sheet 2 Fla. 6

. I ../NvNTORr ELMER h. hw cl? Evy/w 45 ATi' APA/EY Patented June 20, 1950 MECHANICAL PENCIL HAVING MEANS FOR SHARPENING THE LEAD Elmer H. Kuper, Cheyenne, Wym, assignor offive per cent to Wilbur A. E. Mitchell, Greeley, Colo.

Application April 24, 1947, Serial No. 743,541

This invention relates to mechanical pencils, in which the lead is moveable with'relation to the guidetherefor, and having means for sharpening the lead.

It is a principal object of this invention to provide a pencil having a single spring-tensioned lead sharpening means forsharpening action of the lead as the lead is projected.

Another objectof this invention is to provide a pencil having a 'leadsharpening'means which is normally a part of the inner lead supporting guide, constructed-to support the lead when not in sharpening position.

Another object of this invention is to provide such a pencil with a method of mounting the lead cutting means'whereby it may be replaced with another sharpening means for accomplishing a different angular cutting of the lead when desired.

A further object isto provide a pencil with a novel lead cutting means havinga taper governing shoe, normally spring-tensionally resting in the lead channel,- and with the taper governing shoe designed to control the angle of the taperedpoint to be cut in the. lead by the. cutting edge thereof.

Various other objects and advantages will appear evident from the accompanying drawings and detailed description. Like reference numbers and. characters have been used to represent like parts in the different illustrations throughout the drawings, in which Figure l is a longitudinal cross-sectiona1 View of a pencil in retracted position of the plunger;

Figure 2 is a similar view but with the plunger in closed position;

Figure 3 is a cross-sectional view taken upon the line 3-3 of Figure 2';

Figure 4 is a similar view to that shown in Figure 3, but illustrative of another modification of my sharpening means or cutter;

Figure 5 is an enlarged diagrammatical view illustrative of the operation of the lead with my novel cutter means, in different sized construction of the cutter and taper governing shoe, showing the relationship thereof to the degree of taper of the point of the lead capable of being cut thereby;

Figure 6 is an enlarged view of the inner lead guide and sharpening means of Figure 1 positioned before lead sharpening action is commenced.

Figure 7 is a similar view to that shown in Figure 6, but after several longitudinal sharpening strokes of the leadhave been caused in one rotary position of the lead;

14-Claims. (Cl. 12il15) Figure 8 is another enlarged diagrammatical view of my spring-tensioned cutter of Figure 1, illustrative of the positions thereof before and after completion of sharpening operation of the lead, and before the lead is projected outwardly of the pencil;

access to the lead on that side. The inner guide Figures 9 and mare-similar views to Figures 6 and 7, respectively, except with the inner guide and outer pencil point being of less tapered dimension, and with a cutting means designed to produce a less tapered point to the lead;

Figure 11 is illustrative of a finished leadsharpening operation of the modification illustrated in Figures 9 and 10, to show the lead supporting action of-the-cutting means in that finished position;

opening it designed to receive, support and guide the lead as it is projected forwardly out of the pencil. There is-an extension l2 of member ll provided on one side only thereof opposite the sharpener M, so that the'sharpener it may have is preferably screw-threaded into the barrel. A sharpening member, generally designated as I 4, consisting of a spring-tensioned blade or member is mounted, as illustrated, opposite from the extension l2 and by means of an enlargement I5 thereof being slidablyinserted into a groove or slot 3 3 provided-asillustrated in member H. At the extreme outerend of the sharpener member M, I provide a slightrounded head enlargement thereof ll, having a knife-likelead sharpening blade it, as illustrated; The-enlarged head portion' ll acts as a taper governing shoe, as will be explained. The-cutter blade it, of the head I1, is designed to extend into the path or course of travel of the lead, as his projected forwardly for extension from the point of the pencil, by virtue of the sharpener 34 comprising a spring-tensioned arm seated at 34. That-tension normally causes the taper-governing shoe H to rest against the channel side of the extension l2 when the lead is retracted, asin Figure 1. Each time the lead is projected forwardly of the pencil as illustrated, the lead pushes the spring sharpener i l to one side as the lead is projected forwardly between the sharpener head ll and the extension 12. It will be seen that each time the lead is so projected the cutting edge It will shave a small portion off of the 1ead,;as the lead passes the cutting blade [6, as illustrated in Figures 2, '7, and 10, due to the tension of member l4 pressing blade I6 normally into the path of the projected lead. The lead is designated by the numeral I8. Reference numeral I 9, of Figures 2, 7 and 10, represents that portion of the lead which will be shaved or cut away in preparing the lead point, upon plunger operation of the pencil, as will be more fully explained. An outer conical hollow pencil point 28 is screw fastened over the inner lead supporting guide, to the barrel, such as by being screw threaded onto an extension of the flange or collar of guide II, as illustrated. An outer opening 2| is provided at the tip of the point 20, adapted to receive and support the lead as it is projected therethrough, by being substantially of the same diameter as the lead. Referring to the enlarged diagrammatical views and 8, it is to be noted that the extension or lead channel side edge of the cutter head of each sharpening member I4, Ma and Nb, respectively extending from the contact point I Go of each cutter edge opposite the lead channel to the taper-governing shoe N, Na and Ilb, respectively, is slightly concave in contour, which is designed to help prevent the cutter blade I6 from slipping out of cutting operation during the shaving of the lead. That concavity tends to dig or hold the cutting edge point Ilia in the lead, during the projection cutting stroke. That feature is accentuated by the normal spring tensioned pressure of the shank of the member I 4 toward the member I2, and assures that the point I6a does not jump out of cutting operation before the outwardly or projected cutting stroke of the lead is completed. That concave contour of I4 may be altered as needed, by substituting different contoured sharpening members I4, illustrated as Ma and Mb in Figure 5, so as to alter the degree of sharpness of the point capable of being cut thereby in the lead. The angle of edge I6 is to be noted as provided to assist the cutting point Ifict thereof from slipping out of cutting operation, during sharpening of the lead by IGa, in cooperation with the spring tensioned pressure of the member I4, as explained.

A hollow plunger 22 is slidably inserted into the barrel I B, and has a cut-away portion 23 near the eraser end of the pencil, as illustrated. A projection 32 extends inwardly from a conventional spring clasp 3|, designed to act as a stop means in cooperation with cut-away portion 23, for purpose of limiting the normal retractable position of the plunger, as will be more fully explained. Clasp 3! is suitably fastened to the outside of the barrel at 9. An operable conventional lead holdingmeans is provided in the inner opening 25 of the plunger 22, such as by a tube 24 being wedged therein and adapted for rotary movement therein, and having a spiral groove 28 formed therein adapted for receiving a key 21 from a lead holding member 26. Member 26 is adapted for longitudinal movement within tube 24 by its key traveling along groove 28, and has an opening 29, as illustrated, adapted to wedgedly receive one end of the lead I8. A lead removing pin is provided in the other end of the member 26, as will be understood. Tube 24 has an enlarged head adapted for receiving an eraser 33. Turning of the eraser end. of the tube 24 causes the key 21 to travel in spiral groove 28 for either projecting or retracting the lead, with relation to tube 24, as will be understood.

Upon an insertion of a piece of lead, illustrated as IS in Figure 1, and with the plunger in retracted position, the tip of the lead is ready to be sharpened. That is accomplished by operating the plunger 22 toward the point of the pencil in are represented as A, A or A".

the barrel III, by a longitudinal movement or plunger operation of the plunger 22 to the closed position as illustrated in Figure 2. During that plunger projection the point of of the lead passes by the cutter edge I6 and the taper governing shoe IT, and a portion of the lead adjacent to the point is thereby sharpened or cut by I6 as illustrated in Figure 2. After several such strokes of the plunger moving the lead by the cutter head, against the spring tension of sharpener member I4, all of the lead capable of being cut will have been cut; and then the plunger and erasers heads are together turned a few degrees, and thereby the lead rotated or turned slightly and the same lead cutting action is repeated; and again the lead is turned a few degrees, as just explained, and the'action repeated as often as necessary until a perfect point to the lead has been formed, as illustrated in Figures 8 and 11, as will be read ily understood.

It is to be noted that the cutter tip or contact point Ifia, in the-position of the cutter head illustrated in Figures 1, 5, 6, 8 and 9 before the lead is projected to a point to cause a spreading of the sharpener shank I4 from contact position of the shoe IT with the lead channel I3, is slightly to the left of the longitudinal center line of the lead indicated as 35. This construction permits of the making of a geometrically perfect lead point, in sharpening the lead, and is a novel feature of my invention. It is further to be emphasized that I use only a single lead sharpening means or member I4, which always makes a perfect lead. point after sharpening operation of the lead. Heretofore it has been impossible to make a perfect point, because more than one cutter was used and the cutters were not able to overlap that longitudinal center line of the lead to cause a perfect point to be made, but instead in actual practice they never were able to make a perfect point but a certain amount of blunt or flat surface always remained at the tip of the lead point.

Referring to Figure 5, it will be further obvious that, given my sharpener member common contact point Ilia, of different sharpener members, I4, Ma and Mb, having difierent operating lengths between the contact point I6a of each and the taper governing shoe I'I, Ho and I lb, respectively, may be used, which various lengths I provide dif ferent sharpening members I4, Ma and Mb, each having a different operating length, adapted for use with each pencil. Those sharpeningmembers are interchangeable, by means of the tongue .I5 of a member being removably inserted in groove 34, should it be desired to provide a sharpening member capable of cutting a different type point than the one being used. Each of my sharpening members I4, Ma and Idb, have substantially one common characteristic, namely the type of cutting edge I6, and the angle B thereof, as illustrated, and each with a contact point Ilia as illustrated in Figure 5. The only variation, between different members I4, I la and lb, adapted to cut differently tapered lead points, is in the concavity of the taper shoe II, Na. and I lb thereof, respectively, and the length thereof from point Isa to the extreme end II, lid and I'll), as illustrated in Figure 5, thereby defining the longitudinal angular line extended between the point Ifia and the shoe as shown by T, T and T" of Figure 5. The cutting member I4, illustrated in full lines in that Figure 5, will effect a lead taper or point capable of being cut in the lead,

upon cutting operation, having an angular degree of taper or point illustrated by the reference character T. The next headof the cuttingmember illustrated as I to in dotted lines with the distance- A", between'its contact point l6aiand thetaper governing shoe Ila, will cut anangular point 11- lustrated by the referencecharacter T; and the largest cutter head there illustrated as l4b in dotted lines, having a distance A" between the cutter contact point Mia and .its taper governing shoe l lb, will cause a sharp or'fine tapered point to be cut in the lead of an angle represented by the reference character T".

Referring to the taper governing shoe. head or enlargement ll, of member l-4, illustrated in solid lines of Figure 8, it will be clear that inthe beginning of cutting operation, when the lead is pro jected in the channel l3 to .apointindicated as"- P, the lead presses against the shank of the member l4 and thereby causes it to be moved outwardly of the lead channel, against the spring tension of that member I4, or as illustrated there to the right as, the lead is projected. FiguresQ,

The reference character D indicates the angleotj 3 the cutter edge Hi to the line of taper cut in the lead by the cutter. I makethat angle always greater than a right angle in all modifications of It.

. In operation, to disassemble my pencil for replacing or changing leads the plunger is removed from the barrel loby lifting the projection 32 at the top of the spring clasp 3i, outwardly from the barrel. This can be accomplished by an insertion of a fingernail against the inner side of the ridge 8, which is provided for that purpose, and the projection pulled outwardly, 0n

the seat or pivot 9 of the spring clasp, against the tension of the elongated spring portion 31a, as will be understood; and a similar springing of the projection 32 is accomplished to permit reinsertion of the plunger 32 into thebarrel.

The sharpening member l4, being remova'bly fastened at 34, is adapted to be replaced, should dullness occur, or should a different member be desired to produce a difierent tapered point in the lead, as illustrated in Figure 5. outer point 20 is first removed, and then inner point H, if desired, in replacing member [4, though the operation may be accomplished only by removing the outer point 2!] and then slipping the tongue of M out of its groove and replacing or substituting with the tongue of the next member l4, and replacing the point 20.

Having thus described these preferred embodiments of my invention, it will be readily be seen that many and numerous changes can be made therein, such as of proportion, size, relationship What I claim and desire to secure by Letters Patent is:

1. In a pencil having a point, .a barrel, anonarable leadrlnthe barrel, and meansin the banrel tor holding-the lead and adapted for lonsitw. dinal and. rotatable movement or the lead with" relation to the point, thecombination therewith 1 of aninner leadsupporting, means adjacent the point, and a single spring-tensioned knife lead sharpening means, removably secured to. said lead supporting means, for sharpening the lead, as the lead is projectedoutwardly of the pencil.

said sharpeningmeansbeing adapted to act as additional lead supportin means when the lead" is fullyprojected therebeyond.

2. A pencil as-claimed'in claim: '1, and charac'-- terized by the provision ofthe lead sharpening,-v means positioned at an angle or less than to. the lead projection longitudinal center line, andthe sharpening means havingataper governing; shoe forcontrollingthe angle ofxtaper of the lead.

point to be formed upon movement of the lead with relation to the sharpening means.

3. In combination with a pencil having-a re movable point and means for operating the leadlongitudinally and rotatably with relation to the point, of an inner lead supporting means remov ably mounted adjacent the point, and. asingle spring-tensioned leadsharpening member positioned so as to=normallv rest in thepath of the lead when the lead is retracted therebeyond and adapted-for a cuttingof. the lead only upon an outward projection of the-lead, said spring-tensioned sharpeningmember being removably car'- ried asa part of and by the inner leadsupportin'g' means and comprisinga part of said lead supporting means when the lead is projected outwardly beyond the sharpening member.

4. The combination asclaimed in claimB and characterized by the addition ofthe lead sharpening and supporting means havinga taper governing shoe. for controlling the taper angle of the point to be formed in the lead upon outward projective movement of the lead with relation thereto.

5. In a pencil having a barrel and an inner lead supportingv guide within the barrel, and a lead rotatably and longitudinally movable in said guide,. the combination therewith of a single spring-'tensioned sharpening means for sharpen ingthelead upon projective movement thereof.

6. A pencil as defined-in claim 5, and charac pencil, and said taper governing shoe also comprisingmeans for disengaging said cutting point from the lead upon' projection of the lead beyond' the taper governing shoe.

'7; In a pencil havingan outer point, a barrel;

a lead therein, means for: operating the lead 1011,

gitudinally and rotatably, and inner lead supporting means adjacent the point comprisingan inner'lead point supportingchannel, in combination therewitha removablezsprin-g-tensioned one directional-cutting means included as a part ofsaid inner lead supporting means..said cut-tingmeans being adaptedforsharpening the lead upon longitudinal movementof-the lead in different rotarial positionsof the lead and. for supporting the lead when the lead is projected outwardly therebeyond. i

8. A pencil combination as set iorth in claim 7,

amazes-J:

jection of the lead and having acu'tting point and a taper-g'overning shoe, said cutting means being positio'nedso that its tension normally holds the cuttingpoint thereof in the path of the lead after the leadis retracted inwardly therebeyond, and said cutting point being adapted to extend from one side of the lead to beyond the longitudinal center line thereof when the lead is retracted therebeyond,said taper governing shoe extending outwardly of the cutting means with relation to the pencil 'point and from the cutting point and being adapted for controlling the angle of taper'cut in the lead by the cutting point upon outward projection of the lead, and said taper governing shoe portion of the cutting means be ing the only portion of the cutting means being in leadcontact as part of the inner lead supporting means when the lead is projected outwardly ther'ebeyon'd.

9. In a pencil having a barrel, an inner lead supporting guide within the barrel, and a lead rotatably and longitudinallymovable in said guide, in' combination therewith a single spring-tensioned sharpening means associated with the guide for supporting the lead upon outward projection'pf the lead and comprising additional lead supporting means cooperating with the guide, said sharpening means having a cutting edge and a'taper governing shoejsaid shoe being positioned to normally press against the lead supporting guide channel when the lead is retracted, saidcutting edge having a cutting contact point, said sharpening means having an angular relationship between the contact point thereof and the taper governing shoe lead channelfside surface adapted for controlling the angular taper of the point adapted to be cut in the leadby the cutting edge upon outward projection of the. lead in different rotarial positions of the lead. I

10. In combination, a pencil of the class described having a rotatableand outwardly projectible lead, a hollow outer point for the lead, an inner lead supporting means adjacent and within the point, and, a sprin -tensioned sharpener knife means associated within and adjacent the point and being removably mounted and comprising-la part of said. supporting means, said knife ,means comprising a cutting point adapted toextend from one side of the lead to beyond the extended longitudinal center line of the lead when the; lead is retracted therebeyond, said cutting pointextending at an angle greater than a right angle-with relation to the line of taper point out in the lead by the knife means upon plunger operation of the lead, said cutting point being normally spring tensionally held in the path of the lead when the lead is retracted therebeyond, said knife means also having a taper governing shoe means adapted to ride against the lead after sharpening operation and when the lead is-projected therebeyond, and said cutting point being adapted to be out of cutting contact'relationship with the lead when the lead is projected beyond the taper governing shoe.

--11. A pencil combination as described in claim 10, and characterized by the definition of said knife means having its taper governing shoe and cutting point connected by a concave extension,

during lead sharpening longitudinal and rotary side of the lead to a point beyond the longitudinal center line of the lead when the lead is retracted into the pencil therebeyond, and said knife means having means for lifting the cutting point out of lead contact after the point has been formed'o n the lead and the lead has been project ed outwardly of the pencil and therebeyond said lastna'med means,

13;Ihe combination with a pencil having a barrel, an inner lead guide and supporting mem-f ber removably fastened to said barrel and having an extension therefrom and a lead receiving channel therein, a cut away portion on one side: of said extension, an outer point removably encasing the inner lead supporting guide, a plunger slidably mounted in the barrel, a lead operably mounted in said plunger, means associated with the plunger for effecting rotary and longitudinal movement of the lead with relation to saidlead guide, a spring pocket clasp attached to the outer side of the barrel and having a spring tensione'd projection movably positioned in a limited recess in said barrel for limiting the plunger operation with relation to the barrel, a peripheral recess on the exterior of the plunger adapted to receivethe spring projection from the clasp, said plunger being adapted to be removed from the barrel upon spring tension disengagement of the projection of the clasp out of the recess on the plunger, of a single lead sharpening member spring-tensionally and removably mounted in said inner lead supporting guide on the side thereof adjacent the cut away portion and the.

between the cutting head on the one hand and the extension of the inner lead guide on the other hand, said lead sharpening taper governing member having a portion normally adapted to rest against the lead after the lead has been projected outwardly of the pencil thereof in tensionedirelationship therewith and on the side thereof; in the cut away portion of the extension. of the inner lead guide, whereby said sharpening member also acts as lead supporting means in .that projected position of the lead therebeyond,

and whereby the angle of the taper governing shoe with relation to the contact point of the cutting edge of the sharpening member controls the angleof taper of the point formed in the lead as the lead is projected longitudinally of thepencil, in different rotary positions of the lead. 14. A spring-tensioned sharpener knife, adapted to be removably carried at one end thereof by the point of a pencil of the class described having a longitudinally projectable and rotatable lead,

comprising a spring-tensioned shank and a knifev blade'having a cutting point and a taper governing shoe at its other end, said cutting point being adapted to be normally extended from one side of the lead to beyond the longitudinal center line of the lead, when the lead is retracted therebeyond, by said tension shank, said blade comprising the extension between the shank and the cutting point and being adapted to sharpen the lead upon projective movement of the lead thereagainst, and said taper governing shoe being adapted to ride against the lead and to lift the cutting point out of cutting contact with the lead upon projective movement of the lead therebeyond, the knife surface between the cutting point and the taper governing shoe being of concave contour.

ELMER H. KUPER.

REFERENCES CITED The following references are of record in the file of this patent:

Grimmer July 9, 1929 

